Wheel dressing unit



April 8, 1952 s p, BRQ E- 2,592,241

WHEEL DRESSING UNIT Filed April 25, 1949 2 SHEETS-SHEET 1 F351 H 12 l 27 E WM S April 8, 1952 BRUCE 2,592,241

WHEEL DRESSING UNIT Filed April 25, 1949 2 SHEETS-SHEET 2 In V512 Z 01-Jaogbrd EBr ace Patented Apr. 8, 1952 WHEEL DRESSING UNIT Stanford P.Bruce, Detroit, Mich., assignor to Wheel Trueing Tool Company, Detroit,Mich.,

a corporation of Delaware Application April 23, 1949, SerialNo. 89,289

3- Claims. (01. 125-11)" l The present invention relates to a toolbracket, and more particularly to a tool bracket adapted to rotate asprocket wheel by incremental amounts.

The description of the device of the present invention will be made inconnection with a grinding wheel dressing assembly which has a rotatabletool holder carrying a diamond point therein for resurfacing orretrueing the periphery of a grinding wheel. A mechanism for trueing thesurface of grinding wheels of this type has been described in mycopending application Serial No. 744,749, filed April 29, 1947, entitledGrinding Wheel Dressing Mechanism.

As described in my previously mentioned copending application,extendeduse of a diamond tool in the resurfacing or retrueing of agrinding wheel results in the production of flat surfaces on the diamondpoint. This results in the production of off-center ridges on the faceof the .diamond, causing the useful life of the diamond to be shortened,and impairing its efiiciency as a dressing tool. a

To overcome this difiiculty, I have previously suggested providing arotatable tool holder for the: diamond tool, and means for rotating thetool holder and the diamond tool carried therein upon the completion ofa traverse of the tool across the surface of a grinding wheel. Suchincremental indexing of the diamond tool results in the production of aseries of substantially flat triangular faces on the diamond tool whichterminate at the true center of the diamond. Such periodic indexingoperations not only increase the efliciency of the diamond tool as adressing element, but also prolong the useful life ofsuch dressingtools.

An object of the present invention is to provide a grinding wheeldressing assembly containing means for periodically rotating a dressingtool to present a new cutting face to the surface of the grinding wheel.

Another object of the present invention is to provide a tool bracket forperiodically indexing a rotatable tool holder. 1

Another object of the present invention is t provide a tool bracket forthe purposes mentioned above, which may be easily attached to the guardor bed of a conventional grinding machine, has a simple construction andis easy to manufacture.

Other objects of the present invention will be apparent from thefollowing description of the attached sheet or drawings, in which:

Figure 1 is an elevational view of a grinding wheel dressing assemblyillustrating the dressing I tool in working alignment with a grindingwheel,

and illustrating one form of the present invention;

Figure 2 is a sectional view taken substantially along the line IIII ofFigure 1;

Figure 3 is an enlarged fragmentary view of the tool bracket illustratedin Figures 1 and 2, with a section broken away to show the interiorconstruction; J

Figure 4 is a perspective view of a grinding wheel dressing assemblyillustrating another emthe tool bracket of bodiment of a tool bracket;

Figure 5 is anenlargedfragmentary view of the tool bracket illustratedin Figure 4; and

Figure 6 is a cross-sectional view of the face of the tool bracket takenalong line VI-VI of Figure 5. I

As shown on the drawings:- 7

Reference numeral l0 denotes in generala grinding wheel normally used ona center-type grinder. Enclosing at least a portion of the surface ofthe grinding wheel I0 is a conventional guard II. A rotatable toolholder I2 carrying a diamond tool 13 is mounted for reciprocatory motionacross the surface of the grinding wheel I0 parallel to the axis of thegrinding wheel. The tool holder I2 is rotated by the rotation of asprocket wheel I I which is mounted about the periphery of the toolholder l2.

To provide periodic rotation of the sprocket wheel l4 and the diamondtool carried therein, a tool bracket I5 is provided. In the modificationshown in Figure 1, the tool bracket I5 is attached to a surface of theguard ll parallel to the plane of the grinding wheel l0 and is adaptedto rotate the sprocket wheel it after the dressing tool has completed atraverse across the face of the grinding wheel. In some applications, itis desirable to-attach the tool bracket to the bed of the grindingmachine, rather than to the guard, especially where the guard may bemoved out of position easily.

The tool bracket shown in Figures 1,2 and 3 consists essentially of arectangular shank portion 16 which is formed into a base portion l1 atits lower end. The shank portion [6 is secured to the guard II by meansof bolts i8 and 19 which pass through slots 25] and 2| provided in theshank l6.

A pawl member 22 ha ing a bifurcated portion forming ears 23 and 24 ispivotally mounted to the base I! of the tool bracket l5 by means of apair of pivot screws 25 and 26 which pass through the ears 23 and 24 andare rotatably held in the base [1. A pair of nuts 21 and 28 are providedto anchor the pivot screws 25 and 26 within the cars 23 and 24.

A stop member, consisting of a generally rectangular plate 29 isremovably secured to the base I! by means of an Allen type screw 30. Thestop 29 extends beneath the base I1 and serves to limit the pivotalmovement of the pawl 22 about the-base H of the tool bracket l5. Thestop 23 thus holds the pawl 22 rigid when the sprocket wheel I4 isbrought into contact with the same, thus enabling the sprocket wheel Mto be rotated an incremental amount, but the pawl 22 is free to passover the teeth of. the sprocket wheel l4 when the dressing'assembly isretracted for another pass across the surfaceof the grinding wheel I0.

As best seen in Figure 2, the basaci. the. pawl member 22 has a beveledface 3| to facilitate the. movement of the pawl member 22 over successive. teeth. of the sprocket wheel [4, when the dressingassemblyis'being retracted for another pass across the surface of the grindingwheel.

Another embodiment of the tool bracket of the'invention is shown inFigures4-6, inclusive. This embodiment may be used' where a limitedamount of space is available for thetool bracket andwhere'it is desiredto mount the toolbracket on-thetop portion of the guard assembly ratherthan at a side portion as shown in Figures 1-3.

Figure 4 illustrates a conventional grinding wheel 32- having itsperiphery surrounded by a guard 33. A tool holder 34 carrying a diamondpoint 35 is mounted for reciprocatory' motion across the surface of thewheel 32, in the usual manner. A sprocket wheel 36 is secured to thetool holder 34 as a means for periodically'rotating the same.

The tool bracket'3l, as shown in Figure 4, consists of a generallycylindrical shank 33 which carries'a collar 39'having an adjusting screw45 therein forsecuring the collar 39-around anydesired point alongjtheaxis of the shank 3B; The collar 39 is secured to the guard 33' by meansof screws 4|: and 42. which pass through apertures provided in thecollar 39 and are anchored to the guard 33'. The base of'the' shank 38is formed intoflat portions 43 having a series ofthreaded apertures 44,45 and 46..

A plate 41 havingan elongated slot 48 is secured at any desired angle tothe shank 38 by means of a locking bolt 49 which passes through the slot48 and is threaded into one of the apertures 4445.

A pawl member 50 having its top portion bifurcated into a pair of cars51 and 52 is pivotally mounted to the base of the plate 41 by means of apair of pivot screws 53 and 54- threaded into the ears.5l and 52 andheld therein by means of locking nuts 56 and 51. A stop memberconsisting of a rectangular plate 58 is secured to a center portion ofthe base of the plate 4? and overlies the base of the plate 41. Thestopmember 58 is removably secured to the base of the plate 4! by means ofan Allen type screw 59.

The base of the pawl member 50 has inclined face 55 to facilitateengaging successive teeth of the sprocket wheel 36.

The assembly shown in Figures 4-6 is also provided with a resilientassembly yieldably resisting movement of the pawl 50 when the pawlpasses over successive teeth of the sprocket wheel 36. This resilientassembly contains a leaf spring 60 having a curved lip spaced from. thepawl 50 adapted to contact. the same when the pawl 50 passes betweensuccessive teeth of the sprocket wheel 36. Tension is applied to theleaf spring 60 by a second spring 62 which has a crimped portion 63acting against the leaf spring 50 to hold the same against the plate 41.The springs 60 and 62 are secured to the shank 38 by means of a screw54, carrying a washer 55, and, threaded into the, flat portion 43 of theshank.

From the foregoing it will be apparent that there is herein provided atool bracket adapted to intermittingly rotate a sprocket wheel byincrementalamounts, the tool bracket being easily mounted upon aconventional grinding wheel dressingassembi'y and being easilymanufactured from.inexpensivematerials.

It will, of course, be understood that various details oficonstrnctionmay be varied through a wide. range without departing from theprinciples of this invention and it is. therefore, not the purpose tolimit the patent granted hereon otherwise thannecessitated. by the scopeof the appended claims.

I'claim as my invention:

1. In combination wth a grinding wheel dressing'assembly' having arotatable tool holder carried by said assembly for translatory movementacross. the surface of a grinding wheel, said holder carrying a cuttingtool therein arranged to periodically dress the surface of said grindingwheel, and a guard enclosing at least a portion of said wheel, meanscoacting with said holder atthecompletion of a traverse'of said toolacross the surface of said wheel to rotate said holder comprising ashank secured to said guard, a swingable member; carried by said shank,and a stop member carried by said shank in the path of swingingvmovement. of said. swinging member for limitingthe pivotaLmovement ofsaid swingable, member about said shank.

2. Incombinationwith a grinding wheel dressing assembly having arotatable tool holder barrying a cutting tool therein arranged toperiodically dress thesurface of a grinding wheel, a sprocket wheelcarried by said, holder, for rotating the same, and a guard surroundingat least a portion of said wheel,. means for rotating said holder at thecompletion of a traverse of said tool across the surface ofsaid wheelcomprising a shank secured to said guard, a swingable. pawl memberhaving a bifurcated portion carried by said shank, said pawl having abeveled edge for contacting successive teeth of said sprocket Wheel, anda stop member carried by said shank in the path of swinging movement ofsaid pawl member for limiting the swinging movement of said pawl aboutsaid shank.

3. In combination with a grinding wheel dressing. assembly having a.rotatable tool holder carrying a cutting tool therein adapted toperiodically dress the surface of a grinding wheel, a sprocket wheelcarried by said holder for rotating the same, and a guard surrounding atleast a portion of said wheel, means. for rotating said: tool. holderat. the completion of a traverse ofv said tool" across the periphery ofsaid wheel comprising a shank secured to said guard, a swingable pawlmember having its upper portion formed into a bifurcated portionpivotally carried by the end of said shank, and having a beveled edgefor insertion between successive teeth of said sprocket wheel forrotating said sprocket wheel, and a. stop member removably carried bysaid shank and overlying a portion of 5 6 said pawl to limit the pivotalmovement of said Number Name Date pawl about the end of said shank.936,915 Kustner Oct. 12, 1909 STANFORD P. BRUCE. 1,314,735 Derby Sept.2, 1919 1,880,234. Bullock Oct. 4, 1932 REFERENCES CITED 5 1,965,261Sohulte -1 July 3, 1934 The following references are of record in the2,055,291 Henry l 22, 1936 file of this patent: ,097,784 C018 NOV. 2,1937 2,189,286 Gustafs-on Feb. 6, 1940 N b UNITEDNSTATES PATENTSD t2,435,059 Thompson Jan. 27, 1948 um er ame a e 10 159,124 Tomlinson Jan.26, 1875 FOREIGN PATENTS 566,632 Stuart Aug. 25, 1896 Number CountryDate 821,065 slider May 22, 1906 443,928 France Oct. 3, 1912

